1. Field of the Invention
This invention relates to an exposure control device for a photographic camera, and more particularly to an automatic exposure control device for a photographic camera in which the exposure is controlled even in a flash light photographying condition. In the exposure control device in accordance with this invention, the condition of the scene brightness or the photographing distance is input. Further, this invention more specifically relates to an automatic exposure control device for an amateur photographic camera in which the exposure is automatically controlled both in the normal and flash light photographing conditions regardless of the sensitivity of the film loaded therein.
2. Description of the Prior Art
In a conventional camera with a flash light device or a camera to which a flash light device is attachable, the exposure must be manually controlled taking in consideration various factors such as the guide number (GN) of the flash light device, the aperture size (F) of the camera, and the photographing distance (L) when a picture is to be taken with flash light. In this case, the relationship between the above three factors as GN=F.sup.. L must be taken into account. The account of these factors is complicated and troublesome in the actual operation of the camera.
There is known a camera with automatic exposure control means for ameteur use provided with a condition mark setting device in which one of several condition marks such as weather marks is selected with a dial or slide knob to set the condition of the weather (which indicates the scene brightness) in the automatic exposure control means. This type of camera controls the aperture size according to the set condition. However, this type of camera does not indicate the aperture size on the camera body. Therefore, it is impossible to control the aperture size according to the photographing distance when taking a picture with flash light.
Therefore, it is demanded that the camera has means for setting the photographing distance when the camera is set to take a picture with flash light.
On the other hand, it is known in the art to use a film cartridge provided with a film sensitivity indicating means which indicates the sensitivity of the film loaded therein. The camera adapted to use this kind of film cartridge is provided with a film sensitivity sensing means connected with an exposure control means in which the film sensitivity is sensed by the sensing means and the exposure is controlled taking the film sensitivity into account. The film sensitivity sensing means is electrically connected to the exposure control means, and accordingly, is not able to be connected to a mechanical exposure control device.
Therefore, it is demanded that the camera provided with a mechanical exposure control device is automatically controlled with respect to the film sensitivity indicated on the film cartridge.